| Message ID | a79d8f55eab7ed551ea4e052478b04a107e771c1.1558257666.git.baruch@tkos.co.il (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/2] arm64: dts: marvell: mcbin: set SFP power limit | expand |
On Sun, May 19, 2019 at 12:21:06PM +0300, Baruch Siach wrote: > The Clearfog GT-8K board is capable of supplying power up to 2A to SFP > modules. Make that explicit in the device-tree. Without this property > current kernel does not allow SFP modules that require more than 1A. I do hope you're aware that current is not the same thing as power! You say above "2A" which is a current, but the maximum power figure below is "2W". Given that modules are supplied with 3.3V, and Power = Voltage x Current, this really doesn't work out! Please can you correct both of your patches for accuracy in this regard, thanks. > > Signed-off-by: Baruch Siach <baruch@tkos.co.il> > --- > arch/arm64/boot/dts/marvell/armada-8040-clearfog-gt-8k.dts | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/arch/arm64/boot/dts/marvell/armada-8040-clearfog-gt-8k.dts b/arch/arm64/boot/dts/marvell/armada-8040-clearfog-gt-8k.dts > index 9143aa13ceb1..f275d9420d5b 100644 > --- a/arch/arm64/boot/dts/marvell/armada-8040-clearfog-gt-8k.dts > +++ b/arch/arm64/boot/dts/marvell/armada-8040-clearfog-gt-8k.dts > @@ -63,6 +63,7 @@ > tx-disable-gpio = <&cp1_gpio1 29 GPIO_ACTIVE_HIGH>; > pinctrl-names = "default"; > pinctrl-0 = <&cp0_sfp_present_pins &cp1_sfp_tx_disable_pins>; > + maximum-power-milliwatt = <2000>; > }; > > leds { > -- > 2.20.1 > >
Hi Russell, On Sun, May 19 2019, Russell King wrote: > On Sun, May 19, 2019 at 12:21:06PM +0300, Baruch Siach wrote: >> The Clearfog GT-8K board is capable of supplying power up to 2A to SFP >> modules. Make that explicit in the device-tree. Without this property >> current kernel does not allow SFP modules that require more than 1A. > > I do hope you're aware that current is not the same thing as power! > You say above "2A" which is a current, but the maximum power figure > below is "2W". Given that modules are supplied with 3.3V, and > Power = Voltage x Current, this really doesn't work out! > > Please can you correct both of your patches for accuracy in this > regard, thanks. My bad. I'll fix and resend. Thanks for reviewing. baruch >> Signed-off-by: Baruch Siach <baruch@tkos.co.il> >> --- >> arch/arm64/boot/dts/marvell/armada-8040-clearfog-gt-8k.dts | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/arch/arm64/boot/dts/marvell/armada-8040-clearfog-gt-8k.dts b/arch/arm64/boot/dts/marvell/armada-8040-clearfog-gt-8k.dts >> index 9143aa13ceb1..f275d9420d5b 100644 >> --- a/arch/arm64/boot/dts/marvell/armada-8040-clearfog-gt-8k.dts >> +++ b/arch/arm64/boot/dts/marvell/armada-8040-clearfog-gt-8k.dts >> @@ -63,6 +63,7 @@ >> tx-disable-gpio = <&cp1_gpio1 29 GPIO_ACTIVE_HIGH>; >> pinctrl-names = "default"; >> pinctrl-0 = <&cp0_sfp_present_pins &cp1_sfp_tx_disable_pins>; >> + maximum-power-milliwatt = <2000>; >> }; >> >> leds {
diff --git a/arch/arm64/boot/dts/marvell/armada-8040-clearfog-gt-8k.dts b/arch/arm64/boot/dts/marvell/armada-8040-clearfog-gt-8k.dts index 9143aa13ceb1..f275d9420d5b 100644 --- a/arch/arm64/boot/dts/marvell/armada-8040-clearfog-gt-8k.dts +++ b/arch/arm64/boot/dts/marvell/armada-8040-clearfog-gt-8k.dts @@ -63,6 +63,7 @@ tx-disable-gpio = <&cp1_gpio1 29 GPIO_ACTIVE_HIGH>; pinctrl-names = "default"; pinctrl-0 = <&cp0_sfp_present_pins &cp1_sfp_tx_disable_pins>; + maximum-power-milliwatt = <2000>; }; leds {
The Clearfog GT-8K board is capable of supplying power up to 2A to SFP modules. Make that explicit in the device-tree. Without this property current kernel does not allow SFP modules that require more than 1A. Signed-off-by: Baruch Siach <baruch@tkos.co.il> --- arch/arm64/boot/dts/marvell/armada-8040-clearfog-gt-8k.dts | 1 + 1 file changed, 1 insertion(+)